Please include your question in the body of your message, not just in
the subject.
Word and Excel documents can be moved between Office 2k and Office 2k3
(mostly) without problems. If you use a formatting feature that is new
to Office 2k3, that feature will disappear when opened in O2k and, if
it was saved in O2k, will not reappear when opened in O2k3.
I think that they may have changed the Access database format between
versions, but I don't remember for sure. I think that you can open a
Access 2k database in Access 2k3 in a compatibility more so the
database schema will remain at Access 2k format.